44 ""'<A<>-" t' :-" ;-: .- ".'::': .";::: ::;:.; >:': :.:. ;.::;. :.:.:.::;:::::::.::.:.., CARDS FOR ALL OCCASIONS , ", F .&Ó1 . , nnn .. .... " , ','. ", , . 11 . t RJ E FAIlUR =J n r ,- tlCl r 0 . ' . · t===ilr-\\tr\ n [ tJ URY ÞUTÐ r n i - - " r\I 'HI \11 , ,,' '" r =:!, t -I r 1 RENT INCREAS I P f] ) CROP FAI T I n nt/II r:J l..RV6 HAMPOD n -- I. LUBE. "De. ] n · .., n n .. . fin HAIRc,uT - BTH_ I E_ \ ..: ' tin r I 7'(n( emIttIng a detectable signal, he had bad luck. Considering that he was do- ing this work in his spare time, it was altogether remarkable. During the war, Jansky's and Reber's work finally surfaced, because the cosmic hiss set a practical limit to the sensitivity of radar detectors. The distinguished British radio astronomer Sir Bernard Lovell, in his book "The Story of J odrell Bank," describes how he came to know of it. He writes: Reber's work was published in an Amer_- ican scientific journal during the war, and his observations, together with those of Jansky, consti tu ted almost our total knowledge of the radio waves from spa when the war ended. At that time, I knew about these observations in a circuitous manner and had no conception that their further pursuit was to occupy so much of my post-war career. I remember precisely the occasion on which I first heard about the existence of this cosmic static. We were engaged in a desperate attempt to increase the sensitivity of some of our air- borne radars in order to detect enemy submarines and other land targets at greater range. There were three avenues open to us: increase the transmitter power, increase the size of the aerial, or improve the sensitivity of the receiver. The first was at the limit of current techniques and, in the case of the second r we had already caused consternation amongst the aircraft designers by our demands for large aerials. The improvement of receiver sensitivity seemed the easiest and most obvious venti on of the communica- tions satellite. The idea for a communicatIons satellite -a relay station hovering over a fixed point twenty- two thousand three hun- dred miles above the earth -was first suggested by the science-fiction writer Arthur C. Clarke in 1945. Clarke was a flight lieu- tenant in the Royal Air Force when he thought up the satellite, and he de- scribed it in a paper in the British journal Wireless World. The idea lay dor- mant for nearly a decade, until 1954, when it was revived by the noted Bell engineer and science- fiction writer John R. Pierce, in an address he delivered to a meeting of the Institute of Radio Engineers in Princeton. Pierce became the guiding force in the realization of Clarke's fantasy. He put together the technical de- sign for the satellite, tak- ing advantage of a National Aeronau- tics and Space Administration program to launch a large plastic balloon to help measure the density of the atmosphere at high altitudes. Pierce proposed bouncing radio signals off the balloon, which was known as Echo, and in 1960 this scheme proved successful in transmitting radio signals between New Jersey and California. The same year, a Bell Labs engineer named Arthur B. Crawford built a larger ver- sion of the horn reflector antenna ex- pressly in order to receive the weak sig- nals returning to earth from Echo. It was constructed on Crawford Hill, and four years later Penzias and Wilson used it to detect the cosmic photons. , II 1 FLAT !IRE ' I nr l if' c } /\IEW MooN \ r -- lrTI Fì1 -"r r ' r , /: . . course. Alas! This easy optimism was punctured by a member of my group who respectfully informed us about the exis- tence of cosmic static which must inevita- bly set a limit to the receiver sensitivity which could be realized in practice, and in due course he produced copies of the pa- pers by Jansky and Reber. Jansky seems to have put radio as- tronomy aside after his paper of 1935 and so did Bell Labs, until wen after the war. During the war, Bell became heavily involved in radar research-in particular, working on the problel1T of transmitting and receiving -centimetre- wavelength radio transmissions. In 1942, the Bell radio engineers Har.ald T. Friis and A. C. Beck designed what is known as the horn reflector an tenna. (Friis had been Jansky's su- pervisor at Bell, and helped design the antenna that Jansky used:) The horn reflector antenna, a rectangul'ar cone with a parabolic reflector at one end, has a large opening at the large end, through which microwave signals en- ter. It is in common use today as the microwave radio relay that carries most of this country's long-distance telephone and television signals. Penzias and Wilson made their dis- covery of cosmic black-body radiation with such an antenna. The unlikely series of events that led to that discovery included-the in- R OBERT WILSON was born on Janu- ary 10, 1936, in Houston. His father, Ralph, was a chemical engi- neer and worked for an oil-well- service company in T exas. "My father was managing an operation in which they looked to see what was coming up with the cuttings while a wen was beingndrilled," Wilson recalls. "They looked for evidence that the drillers were passing through an interesting formation. When I was a kid, I used to go around with him to the oil fields, and sometimes we would go into the company machine shop on Saturday